WO2015024654A1

WO2015024654A1 - Method and device for the treatment of water by cavitation between annular structures

Info

Publication number: WO2015024654A1
Application number: PCT/EP2014/002273
Authority: WO
Inventors: Branko Sirok; Matevz DULAR; Martin PETKOVSEK
Original assignee: SIEVA d.o.o. - poslovna enota Idrija
Priority date: 2013-08-22
Filing date: 2014-08-19
Publication date: 2015-02-26
Also published as: US10202288B2; EP3036201B1; CN105683091A; CN105683091B; DE102013013813A1; US20160167983A1; EP3036201A1

Abstract

In a method for the treatment of water by cavitation in a cavitation device, the water to be treated passes through an annular cavitation zone (15) which exists between two mutually opposite annular structures (7, 8) which rotate relative to one another and which have teeth (16, 17) directed substantially axially towards one another. Here, the water flows along cavitation surfaces which are provided on the face sides of the teeth (16) of a first (7) of the two annular structures and which are inclined in the circumferential direction such that, viewed in the relative direction of rotation (B) of the other, second annular structure (8), the spacings between said teeth and said second annular structure increase. The invention also relates to a cavitation device suitable for use with the method.

Description

METHOD AND DEVICE FOR TREATING WATER BY CAVITATION BETWEEN RING STRUCTURES

The present invention relates to a method of treating water by cavitation in one

Cavitating device. Furthermore, the concerns

present invention is intended and suitable for use in such a process

Cavitating device.

Aspects of environmental protection are becoming increasingly important globally. An important aspect of this is the purification of household, industrial and commercial wastewater.

Such wastewater can be contaminated with various pollutants. Accordingly, there are a number of different treatment methods, which are

basically divide into mechanical,

physical, biological and chemical methods. There are already proposals, in the context of the treatment of water, especially wastewater, to destroy harmful organic substances cavitation

use. The idea is that the at

Cavitation occurring, associated with extreme pressure peaks strong pressure pulsations Organic

Destroy substances or compounds or so

break up, that they can be further degraded with further treatment methods. Corresponding proposals for the purification of water

To use cavitation, for example described in WO 2007/076579 Al, EP 1780177 A2 and US 6224826 Bl.

Furthermore, the article by Martin Petkovsek et al. "Rotation Generator of Hydrodynamic Cavitation for Water Treatment" (Separation and Purification

Technology, 2013) with the use of cavitation in the removal of pharmaceutical residues from water. A cavitating device is proposed or

examined, which has two arranged in a housing, in opposite coaxial rotating rotors, which are equipped with each other - forming a gap - opposing projections.

Sideways open into the housing a water inlet and (opposite) a water outlet. In the

Publication will be the influences of additives (hydrogen peroxide) and operating parameters

(Temperature). In one of the embodiments studied, the end faces of the projections of one of the two rotors are beveled in the circumferential direction in the sense that, contrary to the direction of rotation of the relevant rotor, the gap width increases in relation to the projections of the second rotor.

EP 2228134 A2 discloses a device for the treatment of liquid in which cavitation effects are used in the course of deposition, purification and homogenization (eg with the aim of improving the combustion of a liquid fuel). The device comprises a through-flow, a liquid inlet and a

Fluid outlet having housing in which a rotating driven disc (rotor) is arranged with axially oriented projections. The projections of the rotor are on one or more circles

arranged. They stand either the front wall of the

Housing or one housed in this,

opposite to rotating second disc opposite, wherein on the end wall of the housing or the second disc axially oriented on coaxial circles

Projections can be arranged. The projections of the rotor and provided on the end wall of the housing or the second disc projections overlap each other in the axial direction and are arranged for this purpose in the sense "gap" that in each case arranged on a circle projections of the rotor in an annular space penetrate, which exists between two adjacent circles of projections of the end wall of the housing or the second disc.

The same applies to the front wall of the

Housing or the second disc arranged

Projections. The rotating second disc can be arranged on a rotating tube, which forms the liquid inlet.

On an industrial scale, the cavitation of

Water for its treatment has not been used. Obviously, there is no method that, under aspects of reliability, the Efficiency or efficiency and others

practice-relevant aspects is industrially useful.

The present invention is directed to providing a method of treating water by cavitation in a cavitating apparatus which is suitable for industrial use, in particular by allowing efficient treatment of water by cavitation using the method. Furthermore, the present invention is directed to provide a Kavitiervorrichtung suitable for performing such a method.

The above object according to the present invention is achieved by a method of treating water by cavitation in a cavitating device by passing the water to be treated from the inside to the outside through an annular cavitation zone between a fixed ring structure and a rotating ring structure facing this occurs, the two

Ring structures have substantially axially opposing teeth and the water during

Flowing through the Kavitierzone flows along Kavitierflächen, which frontally provided on the teeth of one of the two ring structures and in

Circumferential direction are inclined so that they are in the relative direction of rotation of the other ring structure

considered to increase their distance to the latter. Using this method, relatively large throughputs of water (in accordance with designed cavitating devices) can be effectively and efficiently subjected to treatment by cavitation, whereby the corresponding cavitating device can be made comparatively compact. This is helped by the fact that the annular cavitating zone from the inside to the outside

is flowed through, with one of the two

Cavity ring defining ring structures rotating, the other ring structure, however, is non-rotating executed. This is because the fluidic effects that occur in this way within the cavitating zone promote the conveyance of the water to be treated through the cavitating device. In application of the thus executed Kavitiervorrichtung is a

large-scale implementation of the invention

Method (see above) with comparatively low

Apparative effort possible. It is not fundamentally decisive whether the first, the

Cavity ring structure rotates, i. Is part of a rotor, or - as part of a

Stators - not spinning; Both embodiments come into consideration and have their application technology

specific advantages.

As a special aspect of the efficiency is further emphasized that the Kavitiervorrichtung not only manages with a relatively low power consumption, but that it also has a long life; because the work and (adapted to this) construction of the avitiervorrichtung reduces the risk of damage to the rotor and stator by just the cavitation. A decisive aspect in this respect is that according to the present invention for generating cavitation - by generating local underpressure with high pressure gradients - specifically on cavity surfaces

placed, which are arranged at the end faces of provided on a first of the ring structures, directed towards the other ring structure teeth and inclined in the circumferential direction and over which the water is moved under the action of the other, relative to the first ring structure rotating second ring structure, wherein the Cavitierflächen in the relative

Circumferential movement direction of the second ring structure relative to the first ring structure increase their distance from the second ring structure. In the water, which under the action of the second ring structure, which also has an end face, the teeth of the first ring structure opposite teeth, at high speed on the

Cavitation surfaces of the first ring structure is moved, arises in this way (with a steep

Pressure gradient) local vacuum, which leads to cavitation.

The slope of the Kavitierflächen in the circumferential direction is for typical applications preferably between 2 ° and 10 °. In such a design, the desired effects (cavitation) in to such a degree that an efficient treatment of the water is possible, without at the same time an unduly high risk of damaging the

Cavitiervorrichtung by the resulting

Pressure pulsations arise. As stated, this is an advantageous design for typical ones

Use cases . Depending on the nature of the substance, which is to be destroyed or degraded by means of cavitation effects, other inclinations or slopes of the cavitation surfaces may be advantageous. Incidentally, the individual, arranged on the toothing of a ring structure Cavitierflächen

be differently inclined (or employed).

This can reduce the range of treatment of the

Water with regard to different pollutants and also increases the risk of harmful, the

Lifetime impairing resonances can be reduced. Also, to avoid or reduce resonance effects is favorable when the individual teeth of the first and / or the second ring structure in

Circumferential direction are dimensioned differently and / or if the two ring structures a

have different numbers of teeth.

A suitable cavitating apparatus for use in the method according to the invention comprises, according to another aspect of the present invention, a housing with a water inlet, a

Water leakage and a between them

extending cavity and two in the cavity arranged, opposing ring structures, one of which is a first part of a non-rotating stator and the other, second part of a rotationally driven rotor, wherein both ring structures have substantially axially opposing teeth and define between them an annular cavitating zone, which from the inside to is flowed through by the water inlet fluidly communicates with a radially disposed within the Cavitierzone region of the cavity and the water outlet with a radially outside the Cavitierzone arranged portion of the cavity, wherein the front side of the teeth of the two ring structures, preferably the non-rotating first ring structure, Kavitierflachen

are provided, which are inclined in the circumferential direction such that they increase their distance to the latter in the relative direction of rotation of the other, preferably the rotating second ring structure. The teeth provided on the end face on the second ring structure (which moves in rotation relative to the first ring structure) move the water present in the cavitating zone actively at a predetermined speed over the cavitating surfaces of the first ring structure. In typical order of magnitude for this purpose, for example, speed of the rotating ring structure of between 1000 and 3000 ¹ / _m i _n is suitable.

According to the invention, the water inlet of the

Cavitiervorrichtung according to the invention with a radially disposed within the cavitating region of the Cavity and the water outlet communicating with a region of the cavity arranged radially outside the Kavitierzone so that the Kavitierzone (with a movement component in the circumferential direction) is communicated from the inside to the outside, support those occurring within the Kavitierzone

fluidic effects the promotion of the water to be treated by the cavitating. Regardless and independently of this, the

Cavitiervorrichtung, according to a preferred

Training, have a pumping stage, which promotes the water through the Kavitierzone. Preferably, the pumping stage is arranged upstream, i. between the water inlet and the cavitating zone. Under

However, certain preconditions may also prove to be advantageous for an outflow-side pumping stage arranged between the cavitating zone and the water outlet, the suction effect of which may possibly assist or enhance the cavitation effects in the cavitating zone.

A preferred development of the cavitating device according to the invention is characterized in that the axial distance of the two - the annular

Cavitierzone defining - ring structures is adjustable to each other. As a result, the cavitating device can be adapted by simple means to different tasks and requirements; because otherwise the same boundary conditions, the gradient depends on the local

Pressure pulsations within the Kavitierzone of the Distance from the ring structures to each other

comply.

Preferably, flow channels are arranged at least between the teeth of the second ring structure, which extend over the radial extent of the cavitating zone. Via the said flow channels, which are particularly preferred to the cavitating zone

adjacent areas of the cavity out without

significant reduction of the cross-section are open, the area of the cavity arranged inside the cavitating zone communicates with the outside of the cavity

Cavitating zone arranged region of the cavity.

Such flow channels prove to be particularly advantageous, inter alia with regard to the reliability of the cavitating device according to the invention; because through them foreign bodies can get from that

Water inlet associated region of the cavity to that of the water outlet associated region of the

Reach cavity. Thus lead foreign bodies with

Dimensions larger than the minimum

Gap width or the minimum distance between the two ring structures in the region of the annular

Cavity zone does not damage the

Kavitiervorrichtung. This benefits the efficiency due to the increased operational reliability. Also, between the (the Kavitierflächen having) teeth of the first ring structure more or less pronounced flow channels can be provided. According to yet another preferred embodiment of the present invention increase the

Cavitierflachen in the radial direction corresponding to the flow direction of the Kavitierzone their distance from the second ring structure. In this sense enlarge in the invention from the inside out

perfused cavitation (s.o.) The cavitating preferably their distance from the second ring structure (also) in the direction radially outward. This is advantageous in terms of efficiency. For the corresponding

Inclination or slope of the cavities in the radial direction are - for typical applications - also low angles between 2 ° and 10 °.

Another preferred embodiment of the present invention is characterized in that the

Cavitierflächen are enclosed radially outside of outer guide ribs, which in the circumferential direction in the

Essentially constant distance to the second

Observe ring structure. The said distance of the outer guide ribs to the second ring structure is preferably minimally dimensioned, e.g. only a few millimeters thick or possibly even lower. The guide webs contribute to a directed flow of water along the Cavitierflächen along; they reduce the risk of one

"Short circuit" between the radially inner and the radially outer region of the cavity in a substantially radial direction. They also form a kind of barrier or "sealing" of the Cavitierflächen

opposite to the radially outside of the cavitating zone arranged (eg communicating with the water outlet) region of the cavity, so that the prevailing pressure conditions and the

Pressure ratios in the cavitating surfaces are decoupled to some extent from each other. For the same reasons, it is favorable if, according to yet another preferred development of the present invention, the cavitating surfaces are also bordered radially inward by inner guide webs, which are essentially constant in the circumferential direction

Keep distance to the second ring structure. Such inner webs, to some extent, decouple the pressure ratios in the radially inner ring zone (e.g., with the water inlet

communicating) portion of the cavity on the one hand and in the cavitation on the other. It is particularly advantageous if the outer and inner guide webs are part of the U-shaped pockets enclosing the cavitating surfaces.

According to yet another preferred embodiment of the invention, the (rotating) rotor ring structure is designed as a rotor ring disc, which is mounted on a rotatably driven by a motor, arranged in the cavity support structure. In

In a corresponding manner, the stator preferably comprises a stator annular disc which is mounted on a housing section. This favors an individual

Adaptation of the cavitating device to different tasks and requirements through simple exchange the rotor ring disk and / or the stator ring disk. The above-mentioned support structure can thereby

in particular as a flow-through central

Water guide be executed, which has a radial outlet gap, which is substantially aligned with the gap existing between the ring structures. In a suitable embodiment, a pump stage (s.o.) can be implemented in the central Wasserleitkörper at the same time, which for efficient supply of the water to be treated in the relevant Kavitierzone between the two

Ring structures provides.

The cavitating device according to the invention can ggs.

be executed in several stages by two or more stages are flowed through in cascade succession. In this case, the water outlet of the preceding stage is fluidically connected to the water inlet of the subsequent stage.

Furthermore, according to another one

preferred development of the invention, the

Cavitiervorrichtung have a throttle device, by means of which the flow through the

Change Cavitiervorrichtung or can be set specifically. In this way, the residence time of the

Adjusted in the Kavitierzone water and be adjusted in this way, in particular to the degree of pollution or pollution. In the following, the present invention will be explained in more detail with reference to a preferred embodiment illustrated in the drawing. FIG. 1 shows an exploded view of the present invention

Invention structurally implementing

Kavitiervorrichtung,

FIG. 2 shows the first and second cavities defining the cavitating zone of the cavitating device according to FIG. 1. FIG

Ring structure including the rotor support structure and

Fig. 3, the first ring structure of

Cavitiervorrichtung according to Fig. 1 of the

Gear side.

The cavitating device shown in the drawing comprises a housing which encloses a cavity and is designed in such a way that it has a housing shell 1 and a dense with this

has closable housing cover 2. At the

Housing shell 1 are a water inlet 3 and a

Water outlet 4 is provided, both communicate with the cavity. On the housing cover 2 is a

Electric motor 5 flanged. Furthermore, a mounting bracket 6 is connected to the housing cover 2.

In the cavity, a first ring structure 7 and a second ring structure 8 are arranged opposite each other. The first ring structure 7 is - axially adjustable - fixed inside the housing shell 1; it forms a designed as a stator-ring 9 Stator ring structure 10. In contrast, the second ring structure 8 is connected to a rotor support structure 11, which in turn is connected to the - protruding into the cavity, rotating about the axis A - motor shaft 12; Accordingly, it represents a rotor ring structure 14 rotating relative to the first ring structure 7 (arrow B) and designed as a rotor ring disk 13.

The first and the second ring structure 7 and 8, which together a - fluidically between the

Water inlet 3 and the water outlet 4 arranged - from inside to outside flowed through annular

Cavity zone 15 define, have substantially axially oppositely directed teeth 16 and 17 on. Between the teeth 17 of the second ring structure 8 flow channels 19 are arranged, which extend over the radial extent of the Kavitierzone 15 and open radially outward in the region of the cavity, which communicates directly with the water outlet 4. Also, the first ring structure 7 has pangeordnete flow channels 20 between each adjacent teeth 16.

The end faces 21 of the teeth 17 of the second, rotating ring structure 8 lie in one on the axis A.

vertical plane. In contrast, the end faces 22 of the teeth 16 of the first non-rotating ring structure 7 comprise cavitating surfaces 23 which are inclined in the circumferential direction and in the radial direction. The cavitating surfaces 23 are thus inclined (adjusted), that in each case both in Umfangsriehtung in

Direction of rotation B of the second ring structure 8 and in the radial direction from the inside to the outside increases their distance from the second ring structure 8; of the

Anstellwinkel (the slope) in the circumferential direction is about 6 °. The Cavitierflächen 23 are radially outwardly bordered by outer guide webs 24 and radially inward of inner guide webs 25, each in

Circumferentially a substantially constant

Keep distance from the second ring structure 8 and each part of the Kavitierflächen 23 on three sides enclosing, U-shaped pockets 26 are.

The radially within the Kavitierzone 15 in the

Cavity arranged rotor support structure 11 is designed as a flow-through central Wasserleitkörper 27. This has an inlet nozzle 28 which is aligned with the water inlet 3 of the housing, and a radial outlet gap 29, which substantially with the between the two ring structures 7 and 8

existing gap is aligned, on. The rotating one

Water guide 27 acts - in the sense of a

Radial pump - as a pumping stage 30, which actively promotes the water from the inside to the outside through the Kavitierzone 15.

Claims

claims

Method of treating water by cavitation in a cavitating apparatus by adding the

Treating water from the inside to the outside by an annular, between a fixed

Ring structure (7) and one of these

The two ring structures essentially have teeth (16, 17) which are directed axially relative to one another and the water flows along cavitating surfaces (23) as it flows through the cavitating zone (15) provided on the front side on the teeth (16) of one of the two ring structures (7, 8) and in

Circumferential direction are inclined so that they viewed in the relative direction of rotation (B) of the other ring structure (8) their distance to the latter

enlarge.

A method according to claim 1, characterized in that the water under the action of one of

Cavitiervorrichtung associated pumping stage (30) through the Kavitierzone (15) is promoted.

Method according to one of claims 1 or 2, characterized in that the water is moved under the action of the rotating ring structure (8) with a peripheral component having a direction of movement of the stationary ring structure (7) Cavitierflächen (23) along. Cavitating apparatus for use in the method according to claim 1, comprising a housing having a water inlet (3), a water outlet (4) and a cavity extending therebetween, and two opposed ring structures (7, 8) disposed in the cavity, of which a first (7) part of a non-rotating stator and the other, second (8) part of a rotationally driven rotor, wherein both ring structures (7, 8) substantially axially against each other

directed teeth (16, 17) and have a

define annular cavitating zone (15), which can be flowed through from the inside to the outside by the

Water inlet (3) fluidically communicates with a region of the cavity arranged radially inside the cavitating zone (15) and the water outlet (4) communicates with a region of the cavity arranged radially outside the cavitating zone, wherein

front side of the teeth (16) of one of the two ring structures (7, 8), preferably the non-rotating first ring structure (7), Kavitierflächen (23) are provided which are inclined in the circumferential direction such that they are in the relative direction of rotation (B) the other, preferably the rotating second

Ring structure (8) considers their distance

enlarge the latter.

Cavitating device according to claim 4, characterized

in that a pumping stage (30) is arranged in the cavity, which conveys the water through the cavitating zone (15). Cavitiervorrichtung according to any one of claims 4 or

5, characterized in that the axial distance of the two ring structures (7, 8) to each other

is adjustable.

Cavitating device according to one of claims 4 to

6, characterized in that at least between the teeth (17) one of the two ring structures (7, 8), preferably at least the rotating second

Ring structure (8), flow channels (19, 20)

are arranged, extending over the radial

Extension of the cavitating zone (15) extend.

Cavitiervorrichtung according to claim 7, characterized

in that the flow channels (19) are open to the regions of the cavity adjacent to the cavitating zone (15) without appreciable reduction of the cross section.

Cavitating device according to one of claims 4 to

8, characterized in that the cavitating surfaces (23) in the radial direction corresponding to

Flow direction of the cavitating zone (15) increase their distance from the other ring structure.

Cavitating device according to one of claims 4 to

9, characterized in that the Kavitierflächen (23) are radially outwardly bordered by outer guide webs (24), which in the circumferential direction is a substantially constant distance from the second

Observe ring structure (8).

11. cavitating device according to claim 10, characterized in that the Kavitierflachen (23) are enclosed radially inwardly by inner guide webs (25), which in the circumferential direction a substantially

keep constant distance to the second ring structure (8).

12. Cavitiervorrichtung according to claim 11, characterized

characterized in that the outer and inner

Guide webs (24, 25) are part of the Kavitierflachen on three sides enclosing, U-shaped pockets (26).

13. cavitating device according to one of claims 4 to 12, characterized in that the rotor ring structure (14) as a rotor ring disc (13)

is executed, which is mounted on a by a motor (5) rotatably driven, disposed in the cavity rotor support structure (11).

14. cavitating device according to claim 13, characterized

in that the rotor carrier structure (11) is designed as a continuous central water guide body (27) which has a radial outlet gap (29) which substantially coincides with that between the two ring structures (7, 8).

existing gap is aligned.

15. cavitating device according to one of claims 4 to 14, characterized in that the slope of the Kavitierflächen (23) in the circumferential direction between 2 ° and 10 °.

16. cavitating device according to one of claims 4 to

15, characterized in that the two

Ring structures (7, 8) have a different number of teeth (16, 17).

17. cavitating device according to one of claims 4 to

16, characterized in that teeth (16, 17) at least one of the two ring structures (7, 8) are designed to be different from each other.